Orthopaedic surgery is constantly evolving to lessen the effects of surgery on patients. In order to reduce the amount of post-surgical pain, new methods and tools have been developed in CAS to minimize the invasiveness of surgery. Moreover, CAS systems constantly involve new features to accelerate surgeries.
Also, CAS is more commonly used in surgical rooms, so as to provide precision and accuracy to the surgeon. By way of CAS, position and orientation information is gathered during the surgical procedures, so as to provide to the surgeon real-time visual/digital data about bone alterations, tool navigation, and surgical parameters.
One of the issues pertaining to the efficiency of CAS is the creation of frames of references and the digitization of bone models. In such cases, a plurality of points are digitized on the bone elements intraoperatively, which represents a time-consuming operation.
Hip joint resurfacing surgery involves the introduction of hip joint components in a patient. The acetabulum and the femoral head are resurfaced so as to receive an acetabular cup implant and a femoral head implant, respectively. The femoral head implant consists of a ball head received at an end of the resurfaced femoral head. Therefore, the implanted femoral head and the cup (i.e., acetabular or pelvic implant) coact to create the artificial hip joint. In comparison with total hip joint implanting surgery, the hip joint resurfacing surgery removes a relatively small amount of bone while preserving joint stability.
Different output values are of concern in hip replacement surgery. In order to reproduce a natural and/or improved gait and range of motion to a patient, the position and orientation of the implants, the offset of the femur and the limb length must be considered during surgery. The work of the surgeon during hip replacement surgery will have a direct effect on these output values.
Known hip joint resurfacing surgery techniques presently involve specific tools so as to obtain precise position and orientation for the implants. As various types of reamers are used to resurface the femoral head, a plurality of alignment steps are performed to align the tools with the cuts to be made. It is, for instance, of nonnegligible importance that the femoral neck not be damaged (i.e., notched) by the reamers, to prevent fracture-prone weaknesses in the femoral head. Moreover, the resurfacing must be as precise as possible, for instance, to reduce the amount of cement required for implanting the ball head implant to the resurfaced ball head.